Safety valve

ABSTRACT

A safety system for a pressure fluid container has a blow-off valve to provide communication between the interior of the container and the atmosphere, a hydraulic ram controlling the blow-off valve, a hydraulic pressure feed circuit for the ram which is connected to the interior of the container through a buffer capacity, and pressure sensing means in which the pressure in the container acts in opposition to spring loading to control pilot valve means, so that when the container pressure rises above a predetermined value, pressure is reduced in the hydraulic pressure feed circuit to the ram, allowing the blow-off valve to open.

United States Patent 1191 Gemigniani SAFETY VALVE [75] Inventor: Francois GemignianLMartigues,

France [73] Assignee: Societe DExploitation De Brevets Pour LIndustrie & La Marine Societe Anonyme, Martigues, France 221 Filed: Apr. 12, 1971 [21] Appl. No.: 133,083

Related u.s. Application um [63] Continuation-impart of sin. No. 807,640, March 17,

[11] 3,754,566 1451 Aug. 28, 1973 2,619,109 11/1952 Garrett et a1. 137/488 2,235,304 3/1941 Toussaint 137/488 X 3,276,467 10/1966 Case 137/489 Primary Examiner-Henry T. Klinksiek Assistant Examiner-Robert J. Miller Attorney-William Anthony Drucker [57] ABSTRACT A safety system for a pressure fluid container has a blow-off valve to provide communication between the interior of the container and the atmosphere, a hydrau lic ram controlling the blow-off valve, a hydraulic pressure feed circuit for the ram which is connected to the interior of the container through a buffer capacity, and pressure sensing means in which the pressure in the container acts in opposition to spring loading to control pilot valve means, so that when the container pressure rises above a predetermined value, pressure is reduced in the hydraulic pressure feed circuit to the ram, allowing the blow-ofi valve to open.

3 Claims, 1 Drawing Figure SAEETM- VALVE This is a continuation-in-part' of my co-pending United States Patent application Ser. No; 807640 dated l7th1March 1969 now abandoned.

The invention relates to -a safety system designed to be--fitted to equipment such as containers for'storage or;

transport of fluids, liquids or gases, and in general to all installations where a safetydevice is-required:

Its aim is .to provide bymeans of its constructional features, .a 2 working; precision suited to high-pressure equipment, and to make itpossible: to'ensureremote Preferablythe pilot valve means communicate with the hydraulic feed 'circuitb'etweensaid buffer capacity and the ram Advantageouslythe hydraulic feedcircuit ofth'e ram includes a remotecontrol valve interposed between the buffer capacity and the. ram If desiredb'utterflyyalves are-included inthehydraw.

lie feed. circuit in order to isolate the pressure sensing.

means.

One; embodiment of the invention will" now' be -described by ,wayof example with 're'ference to the accompanying .drawing; Thedevice .is shown. diagrammatically -.as a whole.

The, devicecomprises ablow-off' valvel, a-pressure snsingmeans .2 which operates thetblow-off valve l and intermediate piping -3,*4--and 5,=-.and a. bufier container 6'.

The blow-off valvel :is constituted, by" a casing. 7

whichis mounted .onto the container to. be-protected 2 2,'a',valve member s whichiis urged into its closed-pos'itionby means ofa hydraulic ram l0,-and an outlet 9' forthe fluid to bereleased. The pressure sensing means 2.is provided :with an upper cylinder l l in :which a thrust piston. :12 is providedpthethrust piston. 12 .is connected toarod l3. and. acted upon by aspring 14. Thepressureexerted upon the thrust piston 12 'by thespringM is adjustable .by

means of a'threaded mounting-29=for the spring l4. Thethreaded mounting29'is engaged Iwithathreadedportionz30ot the framework-of the pressure sensing means 2; Rod- 13 acts on.-the stem of 'a .valve v.member 15.

against. spring means;

- Adjacentto valve member :15 are a pressurereducer l6,'- a. freeslidablemember -l7 "and a filter element 18 whichareallfed by piping 19.

24, 25,26 and.27 are butterfly valves, valve24 being. closed duringnormalsoperatiomvalves 25, 26and 27 being .open..

The pressure in'container '22 is transmitted through thepiping 5 and then through piping dto'the upper cyl-- inder 11; when the pressure in the-upper cylinder ll exceeds the pressure imposed onthe thrust piston l2 by the spring 14 it willcause thethrust'piston l2and the rod 13 to move downwardly and-open valve 151 Opening of valve 15 will allow fluid to flow-from piping l9"through filter member 18 and pressure reducer l6' past valve l5 and out'through outlet'32."

Pressure is also transmitted through the-piping-S into.

the buffer-container 6 and thence viapiping-2-l and19' to the lower end of the free slidable member l7'via til-'- terelement 18. I

The-free slidable element 17 is-urged downwardly by spring means in combination with pressure acting on its upper'end. However, when valve 15 isopen there is -'a"- release: of pressure in the fluid acting on' theupper'end of element 17; and a relative increase of pressure acting' through piping;l9 onto its -lowerend. Thiscauses element .l7to slideupwardly allowing fluid from" piping 20 to flow through the aperture 33 'past the lower'end of the: element '17 and to escape from the system via outlet 32. With the escape'of fluid through outlet 32 pressure" will be reduced in piping3'which feeds the hydraulic ram 10.

Following reduction-of pressure in piping 3 and the consequential reduction of pressure in'the hydraulic established in piping 20 and 3.

ram 10,- the valve member 8"will lift and all'ow'excess pressure from the container 22 'to escape via outlet '9 Owing to theback pressure in the pipingfillthe valve member 8 will open smoothly but completely.

After-valve member 8 has openedthe pressure container-22 will 'fall and the-pressure'dropwill 'be transmitted via-piping'S and '4 to the upper cylinder 11 of the sensingmeans 2, which will cause the thrust .piston 12and rod 13 to move upwardly under the infliience of spring'il4; Valve l5will then close under the .action' of its own spring. (Valve l5is of the type com-' monly called a clack, ie it is either wholly open or wholly-closed, ithas no intermediate positions).

When valvexls closes fluid entering the pressure sensing means 2 -via piping. 19 passes through filter element l8'and pressure'reducer l6-acts on the upper end of freeslidable member 17 and with the aidofthe spring moves the free slidable member 17 downwards into the aperture 33 thus cutting off the flow through the outlet 32. This in turn causes-pressure to be re- When the pressure in piping 20 and 3 builds 10- will move downwardly causing valve member 8 'to close and the apparatus is reset. 7 Buffer container 6 protects the pressure sensing means 2 from sudden shocks caused by-a rapid rise or fall in pressure. a

It is possible, by opening the butterfly valve 24,-fan'd closing the butterfly valves 25, 26,-to eliminate the part playedby the pressure sensing means 2, while retaining the-possibility of remotely controlling the safety valve by operatinga remote control valve 23.

Thebutterflyvalve 27 makes it possible, by the closing of the butterfly valves 25, 26, 27, completely to isolate the pressure sensing means and possibly toreplace it with an instrument calibrated in advance, this to allow inspection of the pressure sensing means without shutting down the installation.

The remote control valve 23 allows the safety valve to be operated irrespective of the pressure inside the container 22, by manually allowing pressure to drop in piping 3.

up and attains the pressure incontajner 22 the hydraulic ram- This remote control valve 23 may be incorporated in a control panel even a considerable distance from the container.

The sensing means 2 is fitted with the filter element 18 so that the circuits cannot become blocked, and the operating of the free slidable member 17 and the valve cannot be disturbed, which makes the device completely safe in operation. All parts are immediately accessible.

I claim:

1. A safety system for a pressure fluid container comprising in combination, a blow-off valve to provide communication between the interior of the container and the atmosphere, a hydraulic rarn controlling the blow off valve, a hydraulic pressure feed circuit for the ram which is connected to the interior of the container through a buffer capacity, pressure sensing means in which the pressure in the container acts in opposition to spring'loading to control pilot valve means so that when the container pressure rises above a predetermined value, pressure is reduced in the hydraulic pressure feed circuit of the ram, allowing the blow-off valve to open, and valves which when closed isolate the pressure sensing means from the buffer capacity.

2. A safety system as claimed in claim 1, wherein the pilot valve means communicate with the hydraulic feed circuit between said buffer capacity and the ram.

3. A safety system as claimed in claim 1, wherein the hydraulic feed circuit of the ram includes a remote control valve interposed between the buffer capacity and the ram. 

1. A safety system for a pressure fluid container comprising in combination, a blow-off valve to provide communication between the interior of the container and the atmosphere, a hydraulic ram controlling the blow off valve, a hydraulic pressure feed circuit for the ram which is connected to the interior of the container through a buffer capacity, pressure sensing means in which the pressure in the container acts in opposition to spring loading to control pilot valve means so that when the container pressure rises above a predetermined value, pressure is reduced in the hydraulic pressure feed circuit of the ram, allowing the blow-off valve to open, and valves which when closed isolate the pressure sensing means from the buffer capacity.
 2. A safety system as claimed in claim 1, wherein the pilot valve means communicate with the hydraulic feed circuit between said buffer capacity and the ram.
 3. A safety system as claimed in claim 1, wherein the hydraulic feed circuit of the ram includes a remote control valve interposed between the buffer capacity and the ram. 